Possible alternative to nut files?
 

I am trying to find a cheap alternative to nut files, other than the ones already known (nozzle cleaning rods etc.). Came upon some sets of nozzle cleaning drill bits used for 3D printer nozzles (you can Google it - they also show up as ”jeweler drill bits, mini/micro drill bits”). They have them in sizes that match the strings diameter.
Would drill bits work for deepening the slots in a bone nut (not cutting from scratch, just deepening the existing slots), using them just like a file?

Did anyone try these before?

I've found them to be a bit too thin to apply any kind of downward force, particularly for the B and high E string slots. A set of feeler gauges will work better, in my experience. For the .017 B and .013 E for example, you can get a .020 and .015, scuff up the edge and make a file that works very effectively. For the larger strings, I'd combine a few different feeler gauges which, when wrapped with ~400 grit sandpaper, would equal a few thousandth's of an inch wider than the slot I was filing.

This worked well, but I got tired of it (the sandpaper wears through quickly) and eventually just bought a set of StewMac files.

Possible alternative to nut files?
 

If you don't mind the slot appearing wider than the string, a tapered pippin file from LMI will do a nice job. Since the bottom of the slot is round, the string will still sit in the center. Except of course, if you have a Fender headstock with a very slight break angle. The tip of the file is about .025 narrowest, which increases up to about .090. You can have any slot depth and width with just one tool.

This is exactly how I've been doing it for twelve years now. I sharpen the shank end of the drill on a piece of 600 sandpaper on a flat stone plate, then put it in a pin vise, then scrape the slot. Matts67 is right that the drills for the two plain strings are too fragile for practical use. After breaking about two dozen of each, I now use pieces of plain steel string one size larger than target, e.g., .013 for a .012 slot, and .017 for a .016 slot. Sharpen just as a drill, and hold in a pin vise, just as a drill. These are a little flexible, so keep the amount of exposed wire as short as you can get away with.

Besides successfully getting the job done, the bottom of the slots are perfectly radiused to match the string.

This is interesting! Thanks for sharing. So you actually just use the sharpened tip and scrape?

I'm having a hard time picturing this in my mind. Could you post a snap shot? Thanks.

No, not the tip. The other end. And yes, just carefully scrape to lower the slot and form the radius.

Per ac's request, I will post some photos later.

I failed to upload photos here, so I created an album in Flickr. I'm glad ac asked for the photos because I have a guitar on which I sized the the first two slots the same as the string gauge five years ago. They were tight, so i used this exercise to re-size them .001" larger than string gauge.

Note the captions in the photos.

https://www.flickr.com/photos/186387...h/51519542342/

Thanks much for the photos!

I didn't see any text captions anywhere, but I think I get the idea from the photos.

Click on the photo, then look to the left side and below. You'll see the comment under the photo name.

This question comes up regularly.

My method is explained in post #3 of this topic:

https://www.acousticguitarforum.com/...d.php?t=426528

One of these days when I get around to it I'm going to pick up a set of the diamond slotting files from MusicNomad. Sweetwater carries all the sizes. I'm not in a hurry, as I've been using my alternative method for many years without any problem.

Very interesting. Thanks for sharing the photos.

Just ordered a set of micro drill bits and a small hand vise and will give them a test on some bone scrap pieces I have laying around, to see if they are reliable for deepening the nut slots.

After receiving the micro drill bits, although they are able to function as mini files and deepen an existing slot in a piece of bone, I was not able to use them on the actual nut, because the mini vise holding them gets in the way, as it is pretty thick.
I ended up using feeler gauges with 600 grit sand paper (I made sure I used the proper gauge for each string, so that the gauge + the added thickness of the sand paper was spot on - I used a digital caliper for that). Very easy!!!
Turns out this is the easiest way of deepening/adjusting nut slots, without investing in expensive nut files.